The manufacturing process of semiconductor devices can be roughly divided into wafer fabrication, wafer probing and packaging. The wafer probing process includes touching the pads on the wafer with a probe and delivering the test signal from the test station into the wafer through the probe to test various performance of the wafer. The probe structure used in wafer probing should be flexible, so as to keep contacting with the pad when the probe performs touchdowns during the test. The cantilever coaxial probe is currently one of the most commonly available flexible probes structure.
With the development of mobile communication industry, the demand of high-frequency devices in recent years is also growing. In order to reduce the interference of noise in the high-frequency device test, the probe having better noise shielding ability is often used, such as the cantilevered probe made of a coaxial cable. In the production line, the test station may need to perform hundreds of thousands of tests a day, that is, the probe may need to perform hundreds of thousands of touchdowns. Currently, there are a variety of coaxial probes for high frequency wafer probing. However, a common problem of these probes is the vertical deformation of the coaxial probes due to metal fatigue after cyclic touchdowns which cause probe mark shift and unstable contact with the pad.